Traditional aircraft passenger seats may use heavy metallic materials in the backrest structure to endure various stress loads and to create a sufficient load bearing system. A typical backrest may comprise an aluminum or metallic frame with shear panels, side beams, and cross bars to take inflight stress loads and crash loads. A heavy torque tube may also be introduced in the lumbar area, to take torsional loads in the forward direction caused by an asymmetric shoulder belt. Due to the amount of heavy metallic materials used, typical backrest structures may be heavy and costly.